This is part one in a two-part series due to the sheer amount of data we found on this threat and threat actor. This particular attack was a combined spearphishing and exploit attempt. As we’ve seen in the past, this can be a very effective combination.

In this specific example the attackers targeted a feature within Microsoft Word — Visual Basic Scripting for Applications. While basic, the Office Macro attack vector is obviously still working quite effectively. When the victim opens the Word document, an On-Open macro fires, which results in downloading an executable and launching it on the victim’s machine. This threat actor has particularly lavish tastes. This threat actor seem to target high-profile, money-rich industries such as banking, oil, television, and jewelry.

Discovering the threat

The VRT has hundreds of feeds of raw threat intelligence, ranging from suspicious URLs, files, hashes, etc. We take that intelligence data and apply selection logic to it to identify samples that are worthy of review. Using various methods from machine learning to dynamic sandbox analysis, we gather details about the samples – producing indicator of compromise (IOC), and alerts made up of multiple IOCs.

During our analysis we took the last 45 days’ worth of samples, and clustered them together based on a matching set of alert criteria. This process reduced over a million detailed sample reports to just over 15 thousand sample clusters that exhibit similar behavior. Using this pattern of similar behavior, we were capable of identifying families of malware. This led us to discover a Microsoft Word document that downloaded and executed a secondary sample, which began beaconing to a command and control server.

The Malicious Word documents & Associated Phishing campaign

The attacks we uncovered are an extremely targeted spear phish in the form of an invoice, purchase order, or receipt, written specifically for the recipient. For instance, the following is an example message we observed that purportedly came from “Maesrk”, the shipping company.

Starting Friday, July 19, 2013 at 14:45 GMT, Cisco TRAC spotted a new spam campaign likely propagated by the Zeus botnet. The initial burst of spam was very short in duration and it’s possible this was intended to help hide the campaign, since it appears to be targeted towards users of a Trusteer product called Rapport. Within minutes of the campaign starting, we were seeing millions of messages.

This spam impersonated a security update from Trusteer. Attached to this file was the “RaportUpdate” file, which contained a trojan. We’ve identified this specific trojan as Fareit. This file is designed to impersonate an update to the legitimate Rapport product, which, as described by Trusteer, “Protects end users against Man-in-the-Browser malware and phishing attacks. By preventing attacks, such as Man-in-the-Browser and Man-in-the-Middle, Trusteer Rapport secures credentials and personal information and stops online fraud and account takeover.”

It’s important to note that while this end-point solution is designed to protect against browser-based threats, this specific attack is email-based. If the user downloads and executes the attachment via their mail client, it could bypass their browser and the protections of a legitimate Rapport client, entirely. If an end user is tricked into running malicious software for an attack via an avenue the attacker can reasonably predict, it becomes much easier to bypass network security devices and software.

On June 6, 2013, malwaretracker.com released an analysis of Microsoft Office-based malware that was exploiting a previously unknown vulnerability that was patched by MS12-060. The samples provided were alleged to be targeting Tibetan and Chinese Pro-Democracy Activists. On June 7, 2013, Rapid7 released an analysis of malware dubbed ‘KeyBoy,’ also exploiting unknown vulnerabilities in Microsoft Office, similarly patched by MS12-060, but allegedly targeting interests in Vietnam and India. The indicators of compromise (IoCs) listed by Rapid7 match some of the indicators of compromise listed previously by malwaretracker.com.

In the days leading up to #OpUSA, security professionals were busy making preparations for the supposed flood of new attacks coming on 7 May 2013. As we mentioned on 1 May 2013, publicly announced attacks of this nature can have highly volatile credibility. In some cases, the announcements exist only for the purpose of gaining notoriety. In other cases, they are enhanced by increased publicity. By 4 May 2013, speculation arose that #OpUSA was a trap; this likely caused some potential participants to rethink their plans to join. Posts similar to the one below were made on Twitter, Facebook, and YouTube. Read More »

Microsoft has released a “Microsoft fix it” as a temporary mitigation for this issue on systems which require IE8. At this time, multiple sites have been observed hosting pages which exploit this vulnerability. Users of IE8 who cannot update to IE9+ are urged to apply the Fix It immediately.

Update 5/6/2013:

An exploit for this bug is now publicly available within the metasploit framework. Users of the affected browser should consider updating to IE9+ or using a different browser until a patch is released. Given the nature of this vulnerability additional exploitation is likely.

At the end of April a Watering Hole–style attack was launched from a United States Department of Labor website. Many are theorizing that this attack may have been an attempt to use one compromised organization to target another. Visitors to specific pages hosting nuclear-related content at the Department of Labor website were also receiving malicious content loaded from the domain dol.ns01.us. Initially it appeared that this attack used CVE-2012-4792 to compromise vulnerable machines; however, Microsoft is now confirming that this is indeed a new issue. This issue is being designated CVE-2013-1347 and is reported to affect all versions of Internet Explorer 8.

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